Goran Ivanisevic
2001 Wimbledon champion on BBC Radio 5 live

Sam Querrey still nervous, while Andy feels like this is his second home on Centre Court. He can push him on the first set and show him who is boss.

John McEnroe
Three-time Wimbledon singles champion on BBC Two

Sam Querrey has to say to himself, its' not good enough to get to the quarters here. He wants more. He has to show that to people and to his opponent.

Image source, EPA

If he wins today, Andy Murray will remain as world No. 1 when the new rankings are released on Monday 17 July. He will drop to No. 2 if he loses today and Novak Djokovic goes on to win the title.

Murray opens serve and holds to love, Querrey struggling to get near Murray's serve in the opener...

Goran Ivanisevic
2001 Wimbledon champion on BBC Radio 5 live

I don't know him well, but he can hit the ball hard. Geeky or not, he's going to give a tough game to Andy. Although I don't think he's going to win.

Here we go then. Line up the tea and biscuits, maybe a cake or two.

Clear the decks, put your phone on silent and tell the kids to walk home from school.

It's Andy Murray in the quarter-finals at Wimbledon. Watch on BBC Two or at the top of the page.

Play!

Image source, EPA

If you grew up in the 1980s or 1990s this seems frankly ridiculous but Sam Querrey is bidding to become the first American man to reach the semi-finals at a Grand Slam since Andy Roddick finished runner-up here in 2009.

2009!

Roddick’s appearances in the last four at the 2009 Australian Open and 2009 Wimbledon are the only occasions an American man has appeared in the semis at a major in the last decade.

Mind you with Andy Murray, Novak Djokovic, Rafael Nadal and Roger Federer around there haven't been many spots up for grabs...

Leon Smith
Great Britain Davis Cup captain on Radio 5 live

Andy Murray's experienced enough to know you don't always come into these Championships feeling 100%. He's at home every day, he feels good, he's got his team around him.

He might be walking a bit funny and everyone's studying that - probably a bit too much - but I think between points he's walking really well.

Andy has an ability to take away Sam's biggest thing, which is his serve. As long as Andy goes out and serves well, I think he'll keep that record intact.

Image source, AFP

Is that 1-0 Querrey on dogs?

Sorry, not sorry

Image source, Twitter

Here they are, out on Centre Court now! A huge cheer welcomes the players as they start to knock up.

The numbers all favour Andy Murray masively. But Sam Querrey is a tricky customer. He beat Novak Djokovic last year...

Over on Court One, Gilles Muller and Marin Cilic have just wandered out to start their quarter-final.

The winner of their match will go on to play either Murray or Querrey.

You can watch that match - and plenty of doubles matches from around the grounds - over here. Go go go!

Image source, BBC Sport

Image source, Getty Images

This is Andy Murray's 10th quarter-final in a row at Wimbledon, but what is his record like?

Very good.

He has won seven of the last nine, losing only to Rafael Nadal in 2008 and Grigor Dimitrov in 2014.

He has reached three finals, winning two, including last year...

Pat Cash
Former Wimbledon champion on BBC Two

Murray has got to be aggressive. He has to go right down to the forehand and come in some of the time, and tap that weaker side of Querrey.

Andy Murray on the scheduling at this year's Wimbledon: "I don't think it is that difficult to solve.I think they should maybe start the matches earlier on Centre and Court One.

"It's easy to fit two men and two women matches in if you start at 11 or 11:30 like they do on the outside court. Having a bit more time would allow them to fit more matches in. If the scheduling is an issue and something people want to see change, that's something Wimbledon have to look at.

"I've been very lucky. I've got to play my matches on Centre Court and I'm happy and pleased to do that. But if people would rather I play more matches on the outside courts and they switch the scheduling around, that's something that has to be looked at."

Image source, PA

Centre Court filling up now, a hubbub building in the stands. Somewhere among them is the first guy to shout 'Come on Tim!'

His friends will describe him as 'a character.' How we will all laugh.

What are we thinking? Straight sets? A tense five-setter? A few tie breaks?

Let me know on #bbctennis or text us on 81111...

Chris Bevan
BBC Sport at Wimbledon

Image source, BBC Sport

The men's quarter-finalists have all hit the practice courts this morning, including seven-time champion Roger Federer - who caused a bit of a commotion in the spectator's gallery at Aorangi Park. Fed made a wise decision to choose the opposite end of the court to his fans.

Also here is Andy Murray's wisecracking opponent, Sam Querrey, who always seems to be wearing a beaming smile and is ready with a joke.

"I hope that was a photo," he says after posing for some fellow Americans, one of whom was struggling to operate their phone camera. "Otherwise you have got yourself a very awkward five-second video."

Image source, BBC Sport

Olly Murs and Louisa Johnson are at Wimbledon today. They've come up with this belter for him.

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Mats Wilander
Former world number one

I rate him high. He has to come out and be aggressive. If he's too passive, then there's a danger.

Defending champion Andy Murray on BBC One: "I would say, over my career I've played my best tennis here on Centre Court. I love the conditions here and it's showed in the results."

On today's opponent Sam Querrey: "I need to make sure I'm concentrating all of the time and take the chances. When big servers get ahead they're front runners."